branches/zip: Allow the uncompressed page size to be settable by setting

just one parameter: UNIV_PAGE_SIZE_SHIFT.

UNIV_PAGE_SIZE, BUF_BUDDY_SIZES: Define in terms of UNIV_PAGE_SIZE_SHIFT.

BUF_BUDDY_LOW_SHIFT: New macro, to simplify the definition of BUF_BUDDY_LOW
and BUF_BUDDY_SIZES.

PAGE_ZIP_DIR_SLOT_MASK: Relax the compile-time check.  This bitmask must be
one less than a power of two, and at least UNIV_PAGE_SIZE - 1.

include/buf0types.h

@@ -34,14 +34,16 @@ enum buf_io_fix {
 
 /* Parameters of binary buddy system for compressed pages (buf0buddy.h) */
 #if UNIV_WORD_SIZE <= 4 /* 32-bit system */
-# define BUF_BUDDY_LOW		64	/* minimum block size in the binary
-					buddy system; must be at least
-					sizeof(buf_page_t) */
-# define BUF_BUDDY_SIZES	8	/* number of buddy sizes */
+# define BUF_BUDDY_LOW_SHIFT	6
 #else /* 64-bit system */
-# define BUF_BUDDY_LOW		128	/* sizeof(buf_page_t) > 64 */
-# define BUF_BUDDY_SIZES	7
+# define BUF_BUDDY_LOW_SHIFT	7
 #endif
+#define BUF_BUDDY_LOW		(1 << BUF_BUDDY_LOW_SHIFT)
+					/* minimum block size in the binary
+					buddy system; must be at least
+					sizeof(buf_page_t) */
+#define BUF_BUDDY_SIZES		(UNIV_PAGE_SIZE_SHIFT - BUF_BUDDY_LOW_SHIFT)
+					/* number of buddy sizes */
 
 /* twice the maximum block size of the buddy system;
 the underlying memory is aligned by this amount:

include/univ.i

@@ -208,11 +208,10 @@ management to ensure correct alignment for doubles etc. */
 			========================
 */
 
-/* The universal page size of the database */
-#define UNIV_PAGE_SIZE          (2 * 8192) /* NOTE! Currently, this has to be a
-					power of 2 */
 /* The 2-logarithm of UNIV_PAGE_SIZE: */
 #define UNIV_PAGE_SIZE_SHIFT	14
+/* The universal page size of the database */
+#define UNIV_PAGE_SIZE		(1 << UNIV_PAGE_SIZE_SHIFT)
 
 /* Maximum number of parallel threads in a parallelized operation */
 #define UNIV_MAX_PARALLELISM	32

page/page0zip.c

@@ -556,8 +556,11 @@ page_zip_dir_encode(
 		ut_a(heap_no < n_heap);
 		ut_a(offs < UNIV_PAGE_SIZE - PAGE_DIR);
 		ut_a(offs >= PAGE_ZIP_START);
-#if PAGE_ZIP_DIR_SLOT_MASK & UNIV_PAGE_SIZE
-# error "PAGE_ZIP_DIR_SLOT_MASK & UNIV_PAGE_SIZE"
+#if PAGE_ZIP_DIR_SLOT_MASK & (PAGE_ZIP_DIR_SLOT_MASK + 1)
+# error "PAGE_ZIP_DIR_SLOT_MASK is not 1 less than a power of 2"
+#endif
+#if PAGE_ZIP_DIR_SLOT_MASK < UNIV_PAGE_SIZE - 1
+# error "PAGE_ZIP_DIR_SLOT_MASK < UNIV_PAGE_SIZE - 1"
 #endif
 		if (UNIV_UNLIKELY(rec_get_n_owned_new(rec))) {
 			offs |= PAGE_ZIP_DIR_SLOT_OWNED;